The present invention generally relates to needle assemblies. More particularly, the present invention pertains to a safety mechanism for use in connection with needle assemblies including hypodermic needles, catheter needles and other medical instruments.
Needle assemblies used in medical procedures have been and continue to be a concern from the standpoint of healthcare worker safety. Accidental needlesticks with a used needle present the possibility for transmission of disease. The most basic form of needlestick prevention involves the use of a rigid cylindrical cap. The rigid cylindrical cap is positioned over the cannula and engages the hub to which the cannula is connected. During use, the cylindrical cap is removed to expose the cannula. After using the syringe/needle assembly for its intended procedure, the cylindrical cap must be once again mounted on the hub to cover the used cannula. Oftentimes, the healthcare professional tries to reposition the cylindrical cap on the syringe/needle assembly by xe2x80x9cscoopingxe2x80x9d the cylindrical cap with the syringe/needle assembly. As can be appreciated, this may not be an easy or effective technique for repositioning the protective cap on the syringe/needle assembly. Also, the cap may become accidentally dislodged from the syringe/needle assembly, thus exposing the used cannula and presenting a potential danger.
Other proposals have also been made to protect healthcare professionals from needle stick hazards. These proposals are generally divided into three categories: 1) hinged recap devices in which a hinged sleeve is pivoted into a permanently locked position with respect to the cannula; 2) spring-loaded retractable cannula devices in which a spring-connected cannula is activated and the cannula in turn is retracted into the syringe barrel or the syringe plunger; and 3) sliding barrel devices in which the syringe barrel is formed by two concentric cylinders, the outer one of which is slid by the health care worker towards the cannula after use to cover the cannula. Although these assemblies provide some measure of protection against accidental needlesticks, difficulties remain.
For example, hinged recap devices are assembled between the syringe and needle assembly. This construction introduces dead space between the cannula and the syringe, thereby resulting in the waste of expensive medication. Retractable cannula devices run the risk of inadvertently retracting, thus wasting a syringe and once again presenting the possibility of wasting expensive medication. Additionally, the velocity of the cannula retraction could result in the spraying or splashing of fluids or medication, thus actually increasing the healthcare professional""s exposure risk. The sliding barrel design is disadvantageous in that it almost doubles the length of the syringe from the unused position to the used/disabled/engaged position, thus substantially increasing the volume of biohazard waste and possibly creating exposure hazards because the syringe/needle assembly does not adequately fit into the sharps container.
Another disadvantage associated with these alternative designs involves the manufacturing and assembly cost. To make the manufacture of a safety needle or safety syringe cost effective, automated manufacturing equipment must be utilized. However, by virtue of their construction, the syringe/needle assemblies discussed above cannot be manufactured using the same automated equipment that is currently used for producing needle assemblies in which the cannula is simply covered by a cylindrical cap.
The automated manufacture of the needle assemblies mentioned above in which a cylindrical cap covers the needle typically involves fixing the cannula to the hub and then mounting the cylindrical cap on the hub so that the cap covers the cannula. The resulting covered needle assembly can then be packaged and sold as a separate assembly for attachment to and use in connection with any desired syringe. Alternatively, the resulting covered needle assembly can be connected to a syringe to produce a syringe/needle assembly that is then packaged and sold. In the latter case, automated equipment is used to connect the covered needle assembly to the syringe. This automated equipment is designed to handle or accommodate the cylindrical rigid cap that is mounted on the needle assembly for purposes of connecting the covered needle assembly to the syringe. The various types of alternative safety mechanisms mentioned above possess a configuration that is different from the known covered needle assemblies that involve the use of a rigid cylindrical cap. Thus, this automated equipment is unable to handle or accommodate these alternative safety mechanisms and cannot be used to connect these alternative safety mechanisms to a syringe.
In light of the foregoing, a need exists for a safety needle assembly that is constructed to provide the desired protection against accidental needle sticks while at the same time being capable of being handled in an automated manner, preferably through use of existing machinery.
According to one aspect of the invention, a safety needle assembly includes a hub having a proximal end adapted to be connected to a fluid transfer device and a distal end, a cannula having a proximal end connected to the hub and a distal end, a collar mounted on the hub, and a protector provided with a through opening. The protector is movable between an initial position in which the cannula is at least partially covered by the protector and a removed position in which the cannula is uncovered by the protector. A sheath is pivotally mounted on the collar and is positioned in an initial position in which the through opening in the protector is closed by the sheath. The sheath includes a longitudinally extending channel and is adapted to pivot from the initial position in a direction away from the cannula to permit use of the cannula and is adapted to pivot back towards the cannula to a cannula covering position in which the cannula is located within the channel of the sheath. The protector is provided with an engaging part that engages the sheath during movement of the protector from the covering position to the removed position to cause the sheath to automatically pivot away from the initial position. The safety needle assembly is also provided with a mechanism for permanently locking the sheath in the cannula covering position.
According to another aspect of the invention, a safety needle assembly includes a hub having a proximal end adapted to be connected to a fluid transfer device and a distal end, a cannula having a proximal end connected to the hub and a distal end, and a protector having an interior and an opening that communicates with the interior of the protector. The protector is positioned in an initial position in which the protector at least partially covers the cannula and is adapted to be removed so that the cannula is uncovered by the protector. A sheath is pivotally mounted with respect to the hub and is configured to define a channel. At least one cannula engaging projection is provided on the sheath and extends into the channel. The sheath is positioned in an initial position in which at least a portion of the sheath extends through the opening in the protector and into the interior of the protector. The sheath is adapted to pivot away from the cannula and out through the opening in the protector and is adapted, after the protector is removed, to pivot back towards the cannula to a cannula locking position in which the cannula is lockingly engaged by the at least one cannula engaging projection. The assembly also includes a mechanism for preventing the cannula engaging projection from lockingly engaging the cannula when the sheath is in the initial position.
According a further aspect of the invention, a safety needle assembly includes a hub having a proximal end adapted to be connected to a fluid transfer device and a distal end, a cannula having a proximal end connected to the hub and a distal end, a collar mounted on the hub, and a protector mounted on the collar and provided with a through opening. The protector is movable from an initial position in which the protector at least partially surrounds the cannula to a removed condition in which the cannula is uncovered by the protector. A sheath is pivotally mounted on the collar and is positioned in an initial position in which the through opening in the protector is closed by the sheath. The sheath includes a longitudinally extending channel and is adapted to be pivoted from the initial position in a direction away from the cannula and to be pivoted in a direction back towards the cannula to a cannula covering position in which the cannula is located within the channel of the sheath. The safety needle assembly also includes a mechanism for locking the sheath in the cannula covering position. The collar has at least one surface portion which is engaged by a portion of the sheath when the sheath is in the initial position to produce a first frictional engaging force between the collar and the hub sufficient to cause the collar and the hub to rotate together as a unit and which is disengaged from the portion of the sheath when the sheath is pivoted away from the initial position to reduce the frictional engaging force between the collar and the hub to permit the collar to rotate relative to the hub.
In accordance with another aspect of the invention, a safety needle assembly includes a hub having a proximal end adapted to be connected to a fluid transfer device and a distal end, a cannula having a proximal end connected to the hub and a distal end, a collar mounted on the hub, and a protector mounted on the collar and provided with a through opening. The protector is mounted on the collar in an initial position in which the protector at least partially covers the cannula and is movable to separate the protector from the collar so that the cannula is uncovered by the protector. A sheath is pivotally mounted on the collar and is positioned in an initial position in which the through opening in the protector is closed by the sheath. The sheath includes a longitudinally extending channel and is adapted to pivot from the initial position in a direction away from the cannula and is adapted to pivot back towards the cannula to a cannula covering position in which the cannula is located within the channel of the sheath. The protector and the sheath each have an outer surface configured as a part of a cylinder, with the protector and the sheath together defining a cylindrical outer surface when the protector is in the initial position and the sheath is in the initial position.
In accordance with another aspect of the invention, a safety needle assembly includes a hub having a proximal end adapted to be connected to a fluid transfer device and a distal end, a cannula having a proximal end connected to the hub and a distal end, a collar mounted on the hub, and a protector having a wall in which is provided an opening. The protector is positioned in an initial position in which the protector covers at least a portion of the cannula and is movable from the initial position to a removed position in which the cannula is uncovered by the protector. A sheath is pivotally mounted on the collar in an initial position in which at least a portion of the sheath extends through the opening in the wall of the protector. The sheath includes side walls and a back wall defining a channel. The sheath is adapted to be pivoted away from the cannula and out through the opening in the wall of the protector and is adapted to be pivoted back towards the cannula to a cannula covering position in which the cannula is positioned within the channel once the protector has been moved to the removed position. A mechanism is also provided for preventing the sheath in the initial position from freely pivoting out of the opening in the wall of the protector in the absence of a force causing pivoting movement of the sheath.